Conventionally, various methods have been proposed which display 3-dimensional images. Of these, “binocular methods” using binocular parallax are generally used. Specifically, a stereoscopic vision is achieved by providing left- and right-eye images having binocular parallax and projecting them separately on left and right eyes, respectively.
FIG. 22 is a conceptual view for illustrating a “time-division scheme” as one of the typical binocular methods.
In this time-division scheme, the left-eye image and right-eye image are interlaced on alternate horizontal lines of one pixel as shown in FIG. 22, so that the left-eye image and right-eye image will be switched and displayed alternately. The left-eye image and right-eye image therefore have half the vertical resolution compared to that in normal 2-dimensional display mode. An observer should put on shutter glasses that open and close in synchronism with the switching period of the display. The shutter used here opens the left-eye side and closes the right-eye side when the left-eye image is displayed and closes the left-eye side and opens the right-eye side when the right-eye image is displayed. With this arrangement, the left-eye image is observed by the left eye alone while the right-eye image is observed by the right eye alone, to achieve the stereoscopic vision.
FIG. 23 is a conceptual view for illustrating another typical scheme of the binocular methods, namely “parallax barrier scheme”.
FIG. 23(a) is a view showing the principle of the cause of parallax. FIG. 23(b) is a view showing an image frame displayed in the parallax barrier scheme.
In FIG. 23(a), an image in which the left-eye image and right-eye image are interlaced on alternate vertical lines of one pixel as shown in FIG. 23(b), is displayed on an image display panel 401 while a parallax barrier 402 with slits having a slit width smaller than the interval between the pixels for an identical viewpoint is placed in front of image display panel 401, whereby the left-eye image is observed by the left eye 403 alone while the right-eye image is observed by the right eye 404 alone, to achieve the stereoscopic vision.
Incidentally, there is another method, the “lenticular scheme” for achieving 3-dimensional display of an image as shown in FIG. 23(b), which is similarly to the parallax barrier scheme. One example of recording data format used in the lenticular scheme is disclosed by Japanese Patent Application Laid-open Hei 11-41627.
FIG. 24 is a conceptual view showing one example of recording data format of the lenticular scheme. A left-eye image 501 as shown in FIG. 24(a) and a right-eye image 502 as shown in FIG. 24(b) are each thinned to half with respect to the horizontal direction, forming and recording a frame of complex image 503 as shown in FIG. 24(c). Upon reproduction, this complex image 503 is rearranged to form a composite image as shown in FIG. 23(b).
As stated above, in conventional 3D display systems, recording of data is done in a fixed recording data format so as to be suited to the display scheme determined on the playback apparatus side, hence no consideration has been taken to make recording data versatile.
Three-dimensional display involves various necessary information such as the number of viewpoints, the method of thinning and the like other than the display scheme, these pieces of information are not recorded as the recorded data when a single display scheme is used. It is true that if only one identical display scheme is always used, it is not necessary to record these pieces information, but the versatility of recording data is markedly reduced because of this. Just referring to the limited cases where data for the parallax barrier scheme (or the lenticular scheme) is to be recorded, the left-eye image and right-eye image may be recorded as separate sequences, the data may be recorded as a mixed image in which the left-eye image and right-eye image are arranged horizontally half-and-half in one frame as shown in FIG. 24(c), or the data may be recorded as a composite image in which the left-eye image and right-eye image are interlaced on alternate vertical lines of one pixel as shown in FIG. 23(b). Naturally, data of different recording formats should be handled by different processes for display, but since it is impossible to know the data format of data from the recorded data, there is a problem in that it is impossible to know how the data should be processed for display when a third person gets the data.
The present invention has been devised to solve the above problems, it is therefore an object of the present invention to provide an image data generating apparatus for facilitating provision of versatility of image data for 3-dimensional display as well as providing an image data reproducing apparatus for reproducing the data.